Effect of palladium and platinum salts on bacteriophage T4 and its isolated DNA]

The effect of palladium and platinum salts (K2PdCl4, K2PtCl4) on bacteriophage F4 and its isolated DNA in genetic transformation is investigated. Both compounds efficiently inactivated the phage and decreased the transforming activity of donor DNA. The palladium salt exhibited the higher activity. The palladium compounds inhibited the transforming activity of native donor DNA to a greater degree. No difference was observed in the degree of inactivation of the transforming activity of native and denatured DNA under the effect of platinum salt. It is suggested that the difference in the transforming activity of donor DNA treated with the tested compounds reflect the pattern of their interactions with nucleic acids.     

Fatty acid ethyl esters in the liverwort Conocephalum conicum

A series of fatty acid ethyl esters ranging from C₁₄ to C₂₄ was isolated from a hexane extract of the liverwort Conocephalum conicum, these esters accounted for 77% of the extract. The ethyl esters consisting of even-numbered fatty acids were predominant and ethyl palmitate was the major constituent.     

Cyclic adenosine monophosphate content and its regulatory characteristics in Chinese hamster cells with genetically determined changes in the cell surface

The intra- and extracellular concentrations of cyclic adenosine monophosphate (cAMP) in cell line CHO-K1, sensitive (clone 773) and resistant to cytotoxic action of ethidium bromide (EBr), colchicine (Cr) and actinomycin D (ADr), as well as the amount of cAMP in response to isoproterenol, 10% serum and ethidium bromide (EB) in these cells were studied. The increased level of cAMP in EBr- and, Cr-cells, and the decreased one--in ADr cells was found as compared with sensitive cells. The amount of cAMP extruded in the surrounding medium was lower for EBr- and Cr-cells and higher for ADr-cells, in comparison with sensitive cells. All the variants of resistant cells were characterized by a less intensive but a longer reaction for isoproterenol, as compared with sensitive cells. In all the investigated variants 10% serum induced a remarkable increase in the intracellular cAMP by the 2nd hour after their insignificant decrease. 1 mcg/ml concentration of EBr increased intracellular cAMP only in 773-cells. The rules changing the cAMP level to isoproterenol and EB2; are determined by differences in reaction of adenylate cyclase, as it has been demonstrated for the 773- and EBr-cells.     

Fluorescence of acridine orange in the composition of blood and tissues

The interaction of acridine orange with blood albumins and tissue cells from different organs of white mouse has been studied by the spectral luminescence method. It was shown that acridine orange, by penetrating cells or organelles, is able to intercalate between base pairs in the DNA molecule. It was found that the application of acridine orange as a fluorescent probe can influence the metabolic activity of organs.     

Cytoplasmic casein kinase 2 and its substrate proteins in the brain in Alzheimer's disease]

The absence of casein kinase 2 on blots of temporal cortex extracts from Alzheimer's disease patients (ADP) was shown using antiserum to casein kinase 2. Casein kinase 2 activity towards endogenous substrates and casein is 2-5 times less in ADP brain in comparison to normal controls. The fractions of heparin-binding proteins, containing protein substrates for phosphorylation, were isolated from temporal cortex of ADP and normal controls. The total amount of heparin-binding proteins from ADP brains is less than from control brains, and the polypeptide composition of these fractions is much more poop.